For No. 6, move the top left stick of the 4 over to the top of the 1 and move the middle stick of what was originally the 4 up to the top of it, so that it says 7 - 7 = 0 Alternatively, move the top left stick of the 4 to in front of the 1 and move the middle stick of what was originally the 4 to vertically over the minus sign, so that it says -1 + 1 = 0